1. Field of the Invention
The present invention relates to a lighted switch device used in, for example, a control section of a vehicle-installed air conditioner, and, more particularly, to means for preventing undesirable leakage of light from some portion.
2. Description of the Related Art
As shown in FIGS. 4 and 5, a related lighted switch device for a vehicle-installed air conditioner comprises one rotary knob (first operating knob) 1, four push knobs (second operating knobs) 2, 3, 4, and 5 disposed around the rotary knob 1, a case 6 having a front plate 6a to which the rotary knob 1 and the push knobs 2, 3, 4, and 5 are mounted, a rotation detector 8 mounted to a wiring board 7 and accommodated in the case 6, switch elements 9, LEDs 10 (light-emitting diodes serving as light sources), and an annular light conductor 11 for transmitting exiting light 10a from the LEDs 10 to the outer peripheral portion of the rotary knob 1.
This type of related lighted switch device further comprises an annular light-shielding member 13, disposed at a portion of the case 6 where the light conductor 11 is disposed, for preventing light from leaking into gaps 12 formed between pairs of adjacent push knobs, that is, between the push knobs 2 and 3, between the push knobs 3 and 4, between the push knobs 4 and 5, and between the push knobs 5 and 2.
In the related lighted switch device, since the annular light-shielding member 13 is disposed around the annular light conductor 11, it is possible to prevent light from leaking into the gaps 12, disposed between the respective pairs of adjacent push knobs, from the light conductor 11, so that the lighted switch device can be easily seen.
In the related lighted switch device, since the light-shielding member 13, which is formed at the case 6, is disposed in a gap 14 between the rotary knob 1 and the push knobs 2 to 5, the light-shielding member 13 is viewed concentrically with the light conductor 11 in plan view of the lighted switch device. Therefore, the related lighted switch device is not designed well. In addition, the gap 14 is inevitably large. Therefore, also for this reason, the related lighted switch device is not designed well, thereby increasing the size of the switch device. Further, since the light-shielding member 13 is formed at the case 6, a die used for injection molding of the case 6 is large and complicated. Therefore, the lighted switch device, which is a product, is high in cost.